Three Protocols for the Formation of a [3]Pseudorotaxane <i>via</i> Orthogonal Cryptand-Based Host–Guest Recognition and Coordination-Driven Self-Assembly

A novel bis(<i>m</i>-phenylene)-32-crown-10-based cryptand <b>1</b> with a pyridine nitrogen atom outside on the third arm was designed and synthesized. Subsequently, host–guest complexation between cryptand <b>1</b> and a selection of bipyridinium guests has been studied. More interestingly, the [3]pseudorotaxane <b>2</b>⊃<b>5</b>₂ was obtained in three methods by utilizing the noninterfering orthogonal nature of coordination-driven self-assembly and host–guest interactions

The comparison of baseline demographics of asymptomatic and symptomatic groups.

<p>The comparison of baseline demographics of asymptomatic and symptomatic groups.</p

The flow chart of the study.

<p>TCD: transcranial Doppler sonography; MCA: middle cerebral artery.</p

The blood flow spectrum of normal and stenosed MCA.

<p>A. Normal MCA; B. Mild MCA stenosis: mild stenosis was defined as systolic peak velocity 140 to 209 cm/s; C. Moderate MCA stenosis: moderate stenosis was defined as a systolic peak velocity from 210 to 280 cm/s; D. Severe MCA stenosis: severe stenosis was defined as a systolic peak velocity >280 cm/s; E. Occlusive of MCA: We diagnosed occlusion of the MCA if all the basal arteries except the MCA in question were detectable or if the asymmetry index of the affected MCA was<−21% compared with the contralateral MCA with the hemodynamic changes of the intracranial circulation.</p

MES frequency in the asymptomatic and symptomatic groups.

<p>MES frequency in the asymptomatic and symptomatic groups.</p

The comparison of risk factors in MES+ and MES− groups of the symptomatic MCA stenosis group.

<p>Risk factors in MES+ and MES− groups of the symptomatic MCA stenosis group were shown in the figure.</p

MES frequency in different grade stenosed MCA of the asymptomatic and symptomatic patients.

<p>MES frequency was compared among groups both in the asymptomatic and symptomatic patients. The frequency of MES in mild, moderate, severe stenosis and occlusive group of the symptomatic and asymptomatic groups were 4/18 (22.22%) vs 0/30 (0), 13/31 (41.94%) vs 1/28 (3.57%), 30/62 (48.39%) vs 1/39 (2.56%), 2/15 (13.33%) vs 0/11 (0), respectively. The frequency of MES in patients with severe stenosis groups was higher than those with mild stenosis and occlusion in the symptomatic MCA stenosis group with statistical difference (<i>p</i><0.05). The frequency of MES in patients with moderate stenosis was higher than those with mild stenosis and occlusion, although there was no statistical difference (<i>p</i>>0.05). The frequency of MES did not differ between the mild stenosis group and the occlusive group (<i>p</i>>0.05). Besides, we found that except for the occlusive group, the frequency of MES in the symptomatic group was higher than the asymptomatic group in the mild, moderate and severe group, respectively (all <i>p</i><0.05).</p

Three Protocols for the Formation of a [3]Pseudorotaxane <i>via</i> Orthogonal Cryptand-Based Host–Guest Recognition and Coordination-Driven Self-Assembly

A novel bis(<i>m</i>-phenylene)-32-crown-10-based cryptand <b>1</b> with a pyridine nitrogen atom outside on the third arm was designed and synthesized. Subsequently, host–guest complexation between cryptand <b>1</b> and a selection of bipyridinium guests has been studied. More interestingly, the [3]pseudorotaxane <b>2</b>⊃<b>5</b>₂ was obtained in three methods by utilizing the noninterfering orthogonal nature of coordination-driven self-assembly and host–guest interactions

The distribution of risk factors in recruited patients.

<p>Risk factors include the history of the hypertension, diabetes mellitus, ischemic heart disease, dyslipidemia, smoking, drinking. For some patients, risk factors could not be identified.</p

Evidence for an Alternative to the Oxygen Rebound Mechanism in C–H Bond Activation by Non-Heme Fe^IVO Complexes

The hydroxylation of alkanes by heme Fe^IVO species occurs via the hydrogen abstraction/oxygen rebound mechanism. It has been assumed that non-heme Fe^IVO species follow the heme Fe^IVO paradigm in C–H bond activation reactions. Herein we report theoretical and experimental evidence that C–H bond activation of alkanes by synthetic non-heme Fe^IVO complexes follows an alternative mechanism. Theoretical calculations predicted that dissociation of the substrate radical formed via hydrogen abstraction from the alkane is more favorable than the oxygen rebound and desaturation processes. This theoretical prediction was verified by experimental results obtained by analyzing iron and organic products formed in the C–H bond activation of substrates by non-heme Fe^IVO complexes. The difference in the behaviors of heme and non-heme Fe^IVO species is ascribed to differences in structural preference and exchange-enhanced reactivity. Thus, the general consensus that C–H bond activation by high-valent metal–oxo species, including non-heme Fe^IVO, occurs via the conventional hydrogen abstraction/oxygen rebound mechanism should be viewed with caution